MY 55 Gal has been running since late september.
4 weeks ago I got 6 new otos, one of them got sick (some sort of white foam was growing on its tail, doesnt seem to have spread to any other fish) and died 2 weeks ago and another one died yesterday. I didn't make too big of a deal of it because I know that otos have a high chance of dying after being moved to a new tank.
But today I found one of my 6 Corydoras Pafeatus dead, couldnt see anything unusual on its body.
I have about 50 fish in there, most of them small like danios and cloud mountain minnows, the only fish that have the potential to grow are my boesemani rainbow, siamese algae eater and my bristlenose pleco. Tons of plants and a good filter so oxygenation shouldnt be a problem.
The only thing I can think of is that this morning I placed a cantalope with bug sticks in it on a fork and placed it in the tank for my pleco soon after showering and there may have been small amount of soap on my hand and arm, i usually do this in the evening but I was in a hurry and couldnt feed them so I figured this would last them for the day.
I also started adding pottassium supplements in my tank, 2 corks of it every 2-3 days before my oto and Corydoras Pafeatus died.
1 Oto Dead Yesterday, 1 Corydoras Pafeatus Dead Today
your tank is over stocked. 50 fish all abut 2in is to much.
Also is it possible that bottom dwelers starve? My fish are not picky eaters, they jump at everything, including sinking food so I dont know if the Corydoras Pafeatus get enough to eat.
ph 7.4, everything else is 0, I feed 1 bugstick a day for plecos, 1 or 2sinking wafers for Corydoras Pafeatus, and for the other fish I alternate between flakes and frozen shrimps
9 Cloud Mountain Minnow
12 Zebra Danio
1 Ancistrus Pleco (Bristlenose)
1 Clown Pleco
12 otocinclus Vittatus
4 Siamese Algae Eater
5 Corydoras Pafeatus
6 boesemani rainbow
The only stocking issue I really see is the Boesemani and the clown pleco - they need warmer water than everything else. Rehome them and I think you're set :) (though I'd add more cories of the same species, C. paleatus)
You shouldn't have zero nitrates in a cycled tank. What test are you using?
The temperature is kept at 78, I started with cold water with the cloud mountain when I was cycling then I was told theyre fine with warmer water.
Any thought what could have killed the cory?
They're not fine in warmer water - they'll have a shorter lifespan and an increased susceptibility to diseases. Same with the peppered cories, they need much warmer temps. I wouldn't be surprised if the high temps were involved in its death.
Make sure you're really shaking nitrate bottle #2 - bang it against a hard surface quite a bit to mix it well. It's surprising you don't get more nitrates considering how many fish you have and how little water you change, that's all.
74 F or lower is good for them, but that's too low for the Boesemani and the clown pleco.
Glad the plants help with the nitrates!